Analog Control Blocks > PID function block

PID function block process learning and adaptive control parameters

When Process Learning is enabled on a PID block, the following parameters become visible for the block:

Table: Process learning and adaptive control parameters

Parameter

Units

Description

ADP_AUX_REF

None

The user-defined auxiliary state parameter value. ADP_STATE_VAR defines the state parameter.

ADP_AUX_SCALE

None

The high and low scale values, engineering units code, and number of digits to the right of the decimal point associated with the auxiliary state value (ADP_AUX_REF).

ADP_EXCIT_AMP

Percent

The amplitude of the excitation applied to the output if output injection is used.

ADP_EXCIT_DUR

Percent

The duration of excitation as a percentage of the current Time to Steady State value that is applied to the output if output injection is used.

ADP_EXCIT_TMR

Seconds

The time, in seconds, that must pass after any event before output injection can occur.

ADP_EXCIT_TYPE

None

The excitation type:

  • Off - no output injection

  • When Not Identified - when no model is identified

  • On - always

ADP_ID_DELAY

Seconds

The time, in seconds, that must pass after the last identification before a trigger can occur.

ADP_ID_DISABLE

None

The discrete input that can be used to enable/disable adaptation. 

ADP_ID_OUT_LIMIT

None

The output limit calculated from 0 and 100% of the OUT value. Model identification does not occur when values are above and below the limit.

ADP_LAMBDA

Seconds

The Lambda time is the desired closed-loop time constant value. If the Use Lambda Time option is selected in the ADP_OPTIONS parameter, ADP_LAMBDA is writeable and can be used for tuning. If not, ADP_LAMBDA is read-only and calculated based on the model and the value of ADP_LAMBDA_FACTR.

ADP_LAMBDA_FACTR

None

The ratio of the desired closed loop response time constant to the open loop time constant used in adaptive control lambda tuning.

ADP_LICENSED

None

Used to license a PID block for Adaptive Control.

ADP_MAX_BADSAMPL

None

The maximum number of consecutive bad PV samples before identification aborts.

ADP_MAX_FFCHNG

None

The maximum allowed feedforward change over Time to Steady State (TSS) to perform identification.

ADP_MODE_ACTUAL

None

The adaptive control actual mode:

  • Off - The controller calculates new models and tuning for each region but does not adjust the closed-loop tuning parameters. The control loop uses the default tuning parameters.

  • Partial Adapt - The controller calculates new models and tuning for each region and adjusts closed-loop tuning based on the approved models for each region. The controller adjustments are made only for models the user has reviewed and approved.

  • Full Adapt - The controller calculates new models and tuning for each region and automatically adjusts closed-loop tuning based on the last model calculated for each region. No user review or approval is required.

ADP_MODE_TARGET

None

The adaptive control target mode:

  • Off - The controller calculates new models and tuning for each region but does not adjust the closed-loop tuning parameters. The control loop uses the default tuning parameters.

  • Partial Adapt - The controller calculates new models and tuning for each region and adjusts closed-loop tuning based on the approved models for each region. The controller adjustments are made only for models the user has reviewed and approved.

  • Full Adapt - The controller calculates new models and tuning for each region and automatically adjusts closed-loop tuning based on the last model calculated for each region. No user review or approval is required.

ADP_MODEL_DT

Seconds

An array of user-approved model deadtimes (1 per region; 5 maximum).

ADP_MODEL_DT_CL

Percent

The maximum change in model deadtime that can be made at one adaptation in percent of the span of the current deadtime region. 

ADP_MODEL_DT_HL

Seconds

An array of user-specified model deadtime high limits for model identification (1 per region; 5 maximum).

ADP_MODEL_DT_LL

Seconds

An array of user-specified model deadtime low limits for model identification (1 per region; 5 maximum).

ADP_MODEL_G

None

An array of user-approved model gains (1 per region; 5 maximum).

ADP_MODEL_G_CL

Percent

The maximum change in model gain that can be made at one adaptation in percent of the span of the current gain region. 

ADP_MODEL_G_HL

None

An array of user-specified model gain high limits for model identification (1 per region; 5 maximum).

ADP_MODEL_G_LL

None

An array of user-specified model gain low limits for model identification (1 per region; 5 maximum).

ADP_MODEL_IG

None

An array of user-approved model integrating gains (1 per region; 5 maximum).

ADP_MODEL_IG_HL

None

An array of user-specified model integrating gain high limits for model identification (1 per region; 5 maximum).

ADP_MODEL_IG_LL

None

An array of user-specified model integrating gain low limits for model identification (1 per region; 5 maximum).

ADP_MODEL_TC

Seconds

An array of user-approved model time constants (1 per region; 5 maximum).

ADP_MODEL_TC_CL

Percent

The maximum change in model time constant that can be made at one adaptation in percent of the span of the current time constant region. 

ADP_MODEL_TC_HL

Seconds

An array of user-specified model time constant high limits for model identification (1 per region; 5 maximum).

ADP_MODEL_TC_LL

Seconds

An array of user-specified model time constant low limits for identification (1 per region; 5 maximum).

ADP_OPTIONS

None

Options that impact adaptation: 

  • Tune as slave — Adjusts tuning for slave loops (Controller Gain is multiplied by 1.5 and Controller Reset is multiplied by 4.0)

  • Use Target Mode — Allows the use of model identification on top of other systems (Layered Solution)

  • Disable Model Filtering in MAN (1 trigger) — Model changes filtering is disabled for one identification triggered by output change in MAN mode. After successful identification this option is automatically cleared.

  • Use Lambda Time — Tune controller using lambda time instead of lambda factor. The DeltaV InSight Tuning Calculation area shows if lambda time or lambda factor is being used.

ADP_OSC_IDX

Percent

The oscillation index value (0-100%).

ADP_OSC_IDX_LIM

Percent

The oscillation index limit value (0-100%) that triggers an abnormal condition indicator in Inspect.

ADP_OSC_IDX_NOP

None

The number of oscillations that are used to calculate the oscillation index.

ADP_REG_BOUND

Percent

An array of region boundaries.

APD_REG_COUNT

None

The number of regions defined for model identification and adaptive control. Region boundaries are defined by ADP_REG_BOUND.

ADP_REG_DESCR1-5

None

Region descriptions.

ADP_REG_HYST

Percent

The region switching hysteresis that is used to eliminate frequent tuning changes when the state variable value is near one of the boundaries.

ADP_STATE_VAR

None

The State parameter selections on the Region Properties dialog: 

  • AUX - user-defined value that can be calculated from the external reference parameter (ADP_AUX_REF) and the related scale (ADP_AUX_SCALE).

  • OUT - controller output/process model input 

  • PV - Process Variable/process model output 

  • SP_WRK - PV working setpoint 

ADP_TRIG_OPTS

None

The model identification trigger options:

  • Setpoint change in AUTO mode

  • OUT change in MAN mode

ADP_TRIG_OUTCHNG

Percent

The output change that is required to trigger model identification.

ADP_TRIG_SPCHNG

Percent

The setpoint change that is required to trigger model identification.

ADP_TSS

Seconds

Time to Steady State is the estimated time for the process to respond to input changes. If TSS is configured as 0, the block automatically estimates the value after download. Otherwise, the configured time is used until the block's estimation of a new TSS based on the process model identification indicates a 70% difference. Then, the block's estimation is used.

ADP_TSS_MIN

Seconds

The minimum time required for the process to respond to a change in input. The time over which data is collected to support adaptation will always be greater than or equal to TSS_MIN.

ADP_TUN_IDX

Percent

The tuning index (0-100%) that defines the possible improvement over the current tuning if the recommended tuning is used.

ADP_TUN_IDX_LIM

None

The user-defined Tuning Index value limit that triggers an abnormal condition indicator in Inspect.

ADP_TUNING

None

The default tuning rule used for self-regulating processes.